The present invention relates to a rotary electric machine, a linear motor and to a stator used for them.
In a stator of a known rotary electric machine, armature windings are constructed as a single layer distributed winding and are contained in a 3-phase-6-pole stator core having 36 slots, 2 slots per pole per phase, as shown in FIG. 8 and FIG. 9. The stator comprises a stator core 1 which has a back yoke portion 1a formed in a cylindrical shape; a plurality of tooth portions 1b projecting from the inner peripheral face of the back yoke portion 1a and extending toward the center; and slots 2, each formed between adjacent tooth portions 1b. The plurality of armature windings 3 formed in a ring shape are arranged and contained in the slots 2 with an arbitrary slot pitch.
The end coil portion of the armature winding 3 of the rotary electric machine is arranged in a form such that it is pushed and bent into a space near the side face of the back yoke portion 1b of the stator core 1.
In the stator having armature windings 3 that are single layer wound, as described above, winding is performed by initially inserting the windings U1, U2 . . . in the outer peripheral (back bottom) side of the slot 2, and then by inserting the windings V1, V2 . . . in the inner peripheral side of the slot 2, and finally by inserting the windings W1, W2 . . . in the innermost peripheral side of the slot 2 (therein, the reference character attached to individual windings U, V, W represents the windings for U-phase, V-phase and W-phase, respectively). In the winding process, the individual coil end portions of the windings are arranged in the side face of the back yoke portion 1a of the stator core 1, and the coil end portions of the windings W1, W2 . . . finally inserted are arranged onto the upper side of the coil end portions of the windings U1, U2 . . . , W1, W2 . . . for the V-phase and W-phase.
In the coil end portions of the windings in the side face of the back yoke portion 1a of the stator core 1, the height (dimension of the projected portion) H2 of the coil end portion becomes high, because the end portions are arranged with one phase overlapped on the other phase, as shown in FIG. 10(b). Therefore, the axial dimension L2b of the stator, that is, the sum of the projected dimension H2 of the coil end portions and the thickness dimension L2a of the stator core 1 becomes large. In the drawings, the reference character 4 represents a rotor shaft. In a linear motor, this means that the width dimension of the linear motor becomes large.
An object of the present invention is to reduce the axial dimension or width dimension of a stator by reducing the projected dimension of the end coil portions of the windings contained in the stator core.
Another object of the present invention is to further reduce the wiring work cost and the material cost.
The present invention is characterized by a stator comprising a stator core having an even number of slots per pole per phase; and armature windings contained in the slots, the armature windings being wound as a single layer distributed winding. In this stator, one of the slot arranged between two slots containing a first armature winding contains a second armature winding for a phase different from the phase of the first armature winding; one of the slots arranged between two of the slots containing the first armature winding contains a third armature winding for a phase equal to the phase of the second armature winding; and, one of the second armature winding and the third armature winding is arranged in a coil end portion in an outer peripheral side of the first armature winding, and the other is arranged in an inner peripheral side of the first armature winding.
Further, the stator is characterized by the fact that it is constructed by partially performing winding of the armature windings on a plurality of divided cores formed by laminating segments stamped in a sector shape; and then assembling the plurality of divided cores into a cylindrical shape and arranging the armature windings to spread over the divided cores into the individual slots.
Further, the stator is characterized by the fact that an axial dimension of the stator, including the stator core and the coil end portions, is reduced by arranging the coil end portions in a space near a side face of a back yoke portion.
Furthermore, a rotary electric machine is constructed using the stator described above and a rotor which is held so as to be arranged opposite to the stator. A linear motor is constructed using the stator described above and a mover which is held so as to be arranged opposite to the stator.